Denim blue jeans which have been faded, "stone-washed", ice washed, or sand blasted to produce a particular appearance are very popular. However, to produce the desired effect it has been necessary to utilize processes which cause substantial deterioration or degradation of the fabric. Bleaching solutions containing chlorine or actual pelleting of the garment with sand or stones to produce a fashion effect causes damage to the fabric which affects its wear life.
Ozone has been used in the bleaching of cellulosic materials. U.S. Pat. No. 4,283,251 to Singh discloses the bleaching of cellulosic pulp with gaseous ozone in an acidic pH followed by an alkaline treatment.
U.S. Pat. Nos. 4,214,330 and 4,300,367 to Thorsen, which are herewith incorporated by reference, describe a method and an apparatus for treatment of undyed fabrics with a ozone-steam mixture. The process is used to shrinkproof the fabric with a minimum amount of deterioration of the fabric fibers. The ozone treatment reacts with the undyed fibers and provides whiter fibers. The treatment is stated to increase subsequent dyeability and dye fastness of the garment.
W. J. Thorsen et al in their paper entitled, "Vapor-Phase Ozone Treatment of Wool Garments", Textile Research Journal, Textile Research Institute, 1979, p. 190-197, describe the treatment of wool fabrics and garments with ozone and steam to provide shrink resistance to the fabric or garment. The process is based on the reaction of the ozone with the wool fibers.
It should be understood that the term "dye" as used herein is meant to include any of the materials which are used to provide a color to a fabric such as conventional dyes, pigments, or the like.
It should be understood that the term "ozone and steam" as used herein denotes a preferable method of the invention and is meant to include ozone alone or ozone diluted with inert gases.